A passivated and stable silicon (Si) surface is most desirable for subsequent epitaxial growth of single crystal ferroelectrics or high dielectric constant oxides on silicon for non-volatile and high density memory device applications. It is pivotal to establish a passivated yet ordered Si surface, especially for subsequent growth of single crystal oxides, e.g. perovskites. The only reported successful growth of these oxides, such as BaO and BaTaO.sub.3 on Si(100) was based on a BaSi.sub.2 (cubic) template by depositing one fourth monolayer of Ba on Si(100) using reactive epitaxy at temperatures greater than 850.degree. C. See for example: R. McKee, et al., Appl. Phys. Lett. 59(7), pp, 782-784, (Aug. 12, 1991); R. McKee, et al., Appl. Phys. Lett. 63(20), pp, 2818-2820, (Nov. 15, 1993); R. McKee et al., Mat. Res. Soc. Symp. Proc., Vol. 21, pp. 131-135, (1991); U.S. Pat. No. 5,225,01, issued Jul. 6, 1993, entitled "Process for Depositing an Oxide Epitaxially onto a Silicon Substrate and Structures Prepared with the Process"; and U.S. Pat. No. 5,482,003, issued Jan. 9, 1996, entitled "Process for Depositing Epitaxial Alkaline Earth Oxide onto a Substrate and Structures Prepared with the Process". The high temperature requirement for the Molecular Beam Epitaxy surface preparation and template (e.g. BaSi.sub.2) formation truly makes the above mentioned process a high temperature process. The major problems are that this high temperature process requires a much higher thermal budget, promotes diffusion in the structure, and often is not desirable or affordable.
It is highly desirable, therefore, to have a Molecular Beam Epitaxy compatible low temperature process that also provides an ordered wafer surface.
It is a purpose of the present invention to provide a new and improved method of passivating the surface of a Si substrate.
It is another purpose of the present invention to provide a new and improved method of passivating the surface of a Si substrate using Molecular Beam Epitaxy compatible low temperatures.
It is still another purpose of the present invention to provide a new and improved method of passivating the surface of a Si substrate which provides an ordered wafer surface.